Jacob bathes thompson



J. B. THOMPSON. PROCESS OF AND APPARATUS FOR BLEAGHING. No. 293.376.

Patented Feb. 12, 1884.

Nirnn STATES PATIENT Ormcn.

JACOB BAYNES THOMPSON, OF NEVV-OROSS, COUNTY OF KENT, ENGLAND.

PROCESS OF AND APPARATUS FOR BLEACl-HNG.

:SPECIFICATION forming part of Letters Patent No. 293,376, dated February 12, 1884:.

Application filed March 3, 1883.

(No model.)

.70 all whom it may concern: I

Be it known that I, J ACOB Bavnns THOMP- SON, a subject of the Queen of Great Britain, residing at New-Cross, in the county of Kent, England, have invented a certain new and useful Process of Bleaching and Apparatus for the Purpose, part of such process being also applicable to finishing, and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilledin the art to which it appertains to make and use the same.

My invention relates to an improved process of bleaching, and to apparatus for the purpose, part of such process being also applicable to that step in such process or art technically termed finishing, and my invention has for its object the bleaching of yarns, threads, and textile fabrics of vegetable fiber in a more efficacious and expeditious manner than heretofore.

In bleaching linen fabrics according to my process, I proceed as followszl boil the fabric for about three hours in a solution of cyanide of potassium, or sodium-say one-half ounce of the salt to the gallon of water-in order to remove the resinous matter from the fiber, so that the cellulose may be exposed to the subsequent bleaching action, as hereinafter described. The fabric is then washed and again boiled for three hours more in a similar solution. It is then washed again, and is ready to be bleached. lVith cotton fabrics this preliminary boiling is not necessary, except in rare cases when grease or oil may have come in contact with the material, and then the solution should be of about half the previous strength, and the material should be boiled for-about two hours. In ordinary cases, cotton is not boiled at all. It is simply washed in cold water and squeezed. In bleaching, all vegetable fibers or fabrics are treated similarly, the only difference being difference of time of exposure to the bleaching agent. The cotton or linen, after having been treated as above described, is placed somewhat loosely in a suitable air-tight vessel, (nine pounds of the cloth to the cubic foot of space being considered sufficient,) and the vessel is then filled with a weak solution of the bleachingliquor, of a specific gravity of 10012 to 10015,

or about Baum. (About one ounce dry the chlorine.

bleaching-powder-that is, chloride of limeto the gallon will give this strength.) After the vessel has been filled, the liquor is imme diately run out, and is replaced by an atmosphere of carbonic anhydride, (commonly called carbonic acid,) which quicklyliberates the chlorine on the fiber, and this decomposes the water, uniting with the hydrogen and liberating the oxygen, the result of which is to bleach the fiber or fabric. In about 'one hour the whole of the bleaching-liquor on the fiber will have beenthus decomposed, and this operation of moistening the material afresh, and then subjecting it to the action of the gas, should be repeated as many times as may be necessary until the material is of the proper whiteness to be withdrawn from the action of The material is then washed and squeezed. Chlorine, however, always leaves these materials of a yellowish white, part of which is caused by a trace of ferric oxide, which it will acquire even in the course of manipulation. To remove this yellowish tint, and to enhance the whiteness, the material is passed through a solution of oxalic acid, (about two ounces to the gallon of water,) and is squeezed as it passes out of this solution, and is then passed through another solution, which is made by dissolving, in water, triethyl-rosaniline, (commonly called anilineviolet in commerce,) indigo, or other similar compound. If tricthyl-rosaniline be used about onefourth grain to the gallon will be found sufficient, and if indigo be used about twenty grains to the gallon will be required; but I prefer to use triethyl-rosaniline. To

such solution, oxalic acid is added till it be comes of an opaque but bright turquoise-blue; or the material may be passed through the aniline-violet and then be squeezed, and passed through an oxalic-acid solution of the strength above mentioned and again be squeezed, and finally be washed and finished, when it will be found to be of a pearly whiteness. These two latter solutions-via, the aniline-violet and the solution of oxalic acidmay be advantageously used in what is technically termed finishing in the above class of fabrics.

In order that my invention may be more readily understood, I proceed to describe the same with reference to the accompanying drawing, in which the figure represents a pcr-, spective view of apparatus suitable for the purpose.

A is an upper tank, containing bleach-liquor, and B alower tank, also containing bleachliquor.

G is the air-tight bleaching vessel or tank, and D a gas-holder.

a is a pipe leading from the upper tank, A, and b a shaped pipe to show when the bleaching-vessel is full.

c is another U shaped pipe, to allow the bleach -liquor to run out, but to keep the bleaching-vessel sealed against the escape of the gas.

(Z is an opening into the bleaching-vessel 0, through which the materials in it may be examined in order to ascertain whether they are ready to be withdrawn.

0 e are bolts with lever-nuts to secure the cover f of the bleaching-vessel air-tight.

g is a pipe leading to the gas-holder.

h is a chain of a differential pulley, by means of which the cover f may be raised.

2 is a pipe from the pump, and j is the pump, which pumps the liquor from the lower to the upper tank.

7c is a pipe to run off the water when the bleaching-vessel is filled with it, and Z is a perforated false bottom to support the material. There is also a pipe entering at the top of the bleaching-vessel, (not shown in the drawing) by means of which the vessel is filled with water.

Theworking of the process is as follows: After the preliminary singeing and washing, and withlinen after boiling and washing, the fabric is packed loosely in the vessel 0, preferably in the proportion hereinbefore stated, and the vessel 0 is filled with the bleach-liquor. The cover f is then screwed down air-tight, the gas being turned off at g and the spigot or plug in pipe 0. As soon as thevessel is full and the cover screwed down, the flow of the liquor is turned off at a, and the spigot is re moved from pipe 0, and at the same time-the gas is turned on at 9. After standing about an hour, the spigot is again inserted and the bleaching-liquor turned on, and as soon as the vessel fills, the gas will be driven back into the gas-holder till the bleaching-vessel is again full of liquor, and the manipulation is gone through as before, the same gas serving over and over again, the only loss being that absorbed by the small quantity of water it comes in contact with, and by leakage, if there be any. The gas readily displaces the chlorine, which is held loosely by the hydrate of lime, and forms carbonate of lime, or chalk; but the chlorine, on being liberated, decomposes the water, and unites with the hydrogen and forms hydrochloric acid, and this in turn displaces the carbonic acid from the lime and forms calcium-chloride, so that the carbonic-acid gas is again ready to performits office. \Vhen the material is thought to be white enough to be removed from the bleaching-vessel, water is run into such vessel in order to drive the gas into the gasholder. The top 9 is then closed and the water run out at 70. The material can then be examined at the test-hole d. If the material be found to be white enough, the test-hole is closed and the cover unscrewed and raised by the pulley, and the material taken out of the vessel, washed, and squeezed.

tion of oxalic acid, squeezed, .and passed through the blue liquor, and washed; or the material may be passed through the anilineviolet, and then be squeezed and passed through an oxalic-acid solution of the strength above mentioned, and again be squeezed, and finallybe washed and-finished. If it be not quite of the brilliancy required it is again passed through the acid solution, squeezed", and passed through the blue liquor, and washed but usually once will be foundsufficient.

In using triethyl-rosaniline in finishing, the starch is tinted with it'about one-fourth grain to the gallon-and oxalic acid is added till it is of the tint required in the operation turquoise-blue may be prepared out of the starch and added after.

If desired, the linen fiber or material, after being bleached as above described, may be frozen in any suitable freezing apparatus, for the purpose of enhancing its whiteness.

I claim and desire to secure by Letters Patent- 1. An apparatus for bleaching linen and cotton or other vegetable fibers or fabrics, composed of the tanks'A and B for the bleaching- .liquor, the bleaching-vessel C, the gas-holder D, the pipe a, connecting vessels A and O, the pipe 9, connecting vessel 0 and h older 1), dischargepipes b 0 from the vessel 0, and a pump, 3', for transferring the liquid from vessel B to vessel A, substantially as shown and described.

2. The herein-described process for bleaching vegetable fiber, threads, and fabrics, the same consisting in first boiling them in a solution of cyanide ofpotassium, or sodium, then subjecting them to alternate baths of a solution of chloride of lime and of carbonic-acid gas in a closed vessel, and lastly passing them oxalic acid, with suitable washings, all sub stantially as described.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

JACOB BAYNES THGMPSON.

"Witnesses:

- W'ILLIAM LEE,

68 Fleet Street, London. JonN DEAN,

17 Graccchurch Street, London.

The material is then passed through the soluof finishing as ordinarily practiced, or the through a solution of triethyl-rosaniline and 

